Thin film battery having textured layer

A monolithically integrated lithium thin film battery ( 10 ) provides increased areal capacity on a single level (without stacking of multiple cells). The Lithium thin film battery ( 10 ) comprises a substrate ( 12 ) having a surface ( 13 ) textured to comprise a plurality of openings ( 16 ) having sides ( 15 ) angled between 10 and 80 degrees to the surface ( 13 ). A current collector ( 18 ) and a cathode ( 22 ) are formed on the substrate ( 12 ) and within the openings ( 16 ). An electrolyte ( 24 ) comprising lithium phorphous oxynitride is formed by physical vapor deposition on the cathode ( 22 ), thereby providing a layer on the surface of the cathode ( 22 ) and within the openings ( 16 ) of the cathode having substantially the same thickness. An anode ( 26 ) and a capping layer ( 28 ) are then formed on the electrolyte ( 24 ).